A cold open is a pre-credits teaser that airs prior to the show’s opening credits (“Cheers”, “Bewitched”, “The Office” and others have this format). The Brady Bunch always had a short teaser scene that aired after the opening theme but before the first commercial. The teaser always included the producer, writer, and director credits.

“The Cincinnati Kids” is the only episode of the series where the producer/writer/director credits aren’t listed as part of the teaser, but instead are listed after the first commercial. I wonder if, in the original ABC airing, the teaser aired prior to the opening theme, which is why the producer/writer/director credits aren’t included in that segment.

I thought it was because they wanted to show some shots of the park and thought it would save time to have those writer/director credits over that instead of over the first segment.

That also makes sense.